package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    private static final long BEGIN_TIMESTAMP = 1640995200L;
    private static final int COUNT_BITS = 32;


    private StringRedisTemplate stringRedisTemplate;


    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }


    public long nextId(String keyPrefix) {
        //获取当前时间戳
        LocalDateTime now = LocalDateTime.now();

        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);


        //获取redis的全局自增id的时间戳
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));


        //使用redis的自增功能获得序列号
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        return timestamp << COUNT_BITS | count;
    }


}
